South Korea and the United States will begin their annual joint drills in late February as planned to improve their joint combat readiness, the Combined Forces Command said Monday, a move that could affect upcoming cross-border events aimed at improving ties with North Korea.

The allies will hold the computer-based command post exercise, called Key Resolve, from Feb. 24 to March 6, involving about 10,000 South Korean and 5,200 American forces, with 1,100 coming from overseas U.S. bases.

"Key Resolve is a vital exercise to strengthen readiness of the Republic of Korea and U.S. Alliance. I look forward to training with all of our ROK, U.S. and sending state participants," Gen. Curtis Scaparrotti, CFC commander, said in a release. "The scenarios are realistic, enabling us to train on our essential tasks and respond to any crisis which may arise."

On Sunday, the United Nations Command informed the North of the exercise dates and the non-provocative nature of the trainings through the mission at the truce village of Panmunjom, the CFC said. Observers from other nations will ensure that they do not break the armistice agreement signed at the end of the 1950-53 Korean War.

The announcement comes at a crucial time when the two Koreas are in talks to arrange reunions of families separated in the Korean War at North Korea's Mount Kumgang resort Feb. 20-25, dates that partly overlap those of the planned military exercises.

After offering the family reunion event as part of its peace gesture, Pyongyang has repeatedly called on Seoul and Washington to cancel their planned joint drills that could raise tensions. Last week, it lashed out at the U.S. for flying a B-52 bomber over the peninsula last week when the Koreas reached a deal on the family reunions.

But Seoul and Washington have said they would press ahead, calling their military maneuvers defensive exercises.

"As long as South Korean and U.S. forces exist, they should regularly hold necessary drills to maintain combat capabilities," defense ministry spokesman Kim Min-seok said in a briefing. "North Korea is also well aware that the South Korea-U.S. drills are annual trainings defensive in nature. So it is not appropriate to link (the drills) with the family reunions."

So far, Pyongyang has not responded to Seoul's notification of the upcoming drills, Kim said.

The two allies also plan to hold combined field training exercises, called Foal Eagle, which involve a set of ground, air, naval, expeditionary and special operations from Feb. 24 to April 18.

The field training involves 7,500 U.S. American troops, with 5,100 of them coming from abroad, the CFC said, without elaborating details of military assets taking part in the drills.

While some 220,000 South Korean troops participated in last year's training, the number of soldiers is expected to decrease this year as some forces from the Second Operations Command Headquarters have been mobilized to support quarantine efforts to contain the spread of bird flu in the country, according to military officials.

Last year, the U.S. mobilized a nuclear-powered aircraft carrier, F-22 stealth fighters and B-52 nuclear bombers to the peninsula, which drew angry response from the communist state and sharply stoked regional tension.

While consultations are under way to arrange the family reunions, the allies are expected to stage a relatively low-key exercise without involving high-profile nuclear bombers and carriers so as not to stimulate the communist state.

"Last year, North Korea strongly threatened nuclear attacks, sparking concerns among South Korean people. Therefore, several U.S. military equipment, including strategic bombers, came (to the Korean Peninsula) to show off the allies' deterrence capabilities and to assure people," spokesman Kim said. "As the current situation is completely different from last year, the joint forces will only carry out planned drills, which are on similar levels to those of last year."

About 28,500 U.S. troops are stationed in South Korea to help deter North Korean aggression as the three-year conflict ended in a truce, without signing a peace treaty. (Yonhap)